Research On Microstructure And Mechanical Properties Of Fine-grained Casting K4169Alloy By Thermal Control Method

In this paper, fine-grained K4169alloys were prepared by vacuum induction melting,conventional cast K4169alloy was prepared with comparison. The microstructure wereanalyzed by optical microscope and scanning electronic microscope. The mechanicalproperties of the two conditions were studied by the Instron testing machine.The study of microstructures shows that, the conventional cast K4169alloy showsdendrite microstructure, the secondary dendrite arm spacing was220?m, much Lavesphase lies in the dendrite. Fine-grained K4169alloys were composed by the equiaxedgrains. The grain size decreased to50~70?m. The grain size of Laves phase alsodecreased.The study of the mechanical properties of K4169alloy shows that the from-196?to600?, the strength of fine-grained cast K4169alloy is higher than the conventional castK4169alloy. At low temperature (196?and room temperature), the ductile offine-grained cast K4169alloy decreased greatly than the the conventional cast K4169alloy. The study of the creep rupture life shows the creep rupture life of fine-grained castK4169alloy is4.1times higher than conventional cast K4169alloy...